HVAC systems appear to retain their allure for thieves, who seem less interested in climate control than in the value of the copper parts as scrap, both in Washington and throughout the country, authorities say.

In the Washington area, two recent, large-scale HVAC thefts were reported last week in Prince William County, involving equipment with a total value of more than $60,000, police said. In one case, six exterior HVAC systems pieces of were taken from outside a church in Woodbridge, police said. .

Staff members at the First Church of the Nazarene on Smoketown Road told officers on Oct. 30 that equipment valued at $48,000 had been taken overnight, the police said. .

The next day, police said equipment valued about $14,000 was taken from the 18300 block of Quantico Gateway Drive, in the Triangle area.

Later that day, police said, a tip led them to a house in the Woodbridge area, where they found disassembled HVAC parts.

Further investigation led to four arrests, police said. Security specialists say saws and bolt cutters are sometimes used to remove outdoor HVAC equipment.

The pastor of the Woodbridge church, Athan Burch, described the items taken from First Nazarene as heat pumps. He said it did not appear as if the items recovered by the police could be used again.

The church was getting estimates for replacement of its losses, he said.

HVAC thefts have occurred around the country. Victims often find the cost of replacing the missing equipment to far outstrip the price that can be obtained for the copper on the scrap market. In addition, the thefts, depending on the season, can often prevent use of buildings until replacement equipment is installed.

“It has been a nightmare trying to keep an air conditioning unit here,” a spokesman for the library in Shreveport, La. recently told a television station in that area.

One online site indicated that the price of a pound of spot copper has fluctuated for several months around the $3.20 level.

Building management and insurance firms have offered advice on their web sites for preventing HVAC thefts. These include alarm systems and sturdy enclosures.

Copper piping and wiring have also been frequent targets of thieves around the country.